Facile Carbonization of Microporous Organic Polymers into Hierarchically Porous Carbons Targeted for Effective CO2 Uptake at Low Pressures
Facile Carbonization of Microporous Organic Polymers into Hierarchically Porous Carbons Targeted for Effective CO2 Uptake at Low Pressures
复制标题
微孔有机聚合物轻松碳化成分级多孔碳，目标是在低压下有效吸收二氧化碳
DOI：
10.1021/acsami.6b05170
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发表时间：
2016-07-20
影响因子：
9.5
通讯作者：
Tao, Kai
中科院分区：
文献类型：
--
作者：
Gu, Shuai;He, Jianqiao;Tao, Kai
微孔有机聚合物（MOPs）的出现在气体储存和分离（CCS）方面带来了巨大的潜力。然而，在这些聚合物中仅存在微孔通常施加扩散限制，这导致在CCS中MOPs的低利用率。本文中，单一微孔有机聚合物（MOPs）的容易的化学活化导致一系列具有分级介孔-微孔结构和在低压下的高CO2吸收能力的分级多孔碳。MOP-7-10是一种具有简单窄嵌段结构的MOPs前驱体，其BET表面积在479 ~ 819 m（2）g（-1）之间。通过比较不同活化剂对这些MOPs材料碳化的影响，我们发现经KOH活化的优化碳材料MOPs-C显示出独特的分级多孔结构，其主要孔径从微孔到中孔显著扩大，而其微孔率也显著提高，这可通过纤维体积的显著增加（从0.27 cm（3）g（-1）增加到0.68 cm（3）g（-1））来证明。这可能与活化剂KOH在高温下活化导致聚合物骨架的坍塌和结构重排有关。制得的分级多孔炭MOPs-C的BET比表面积明显增加（从819 m2 g-1增加到1824 m2 g-1）。MOPs-C独特的多级孔结构显著提高了CO2的捕集能力，在273 K和1 bar下，其CO2捕集能力分别达到214 mg g（-1）和52 mg g（-1），比目前已知的MOPs-C和多孔炭的捕集能力有上级的提高。高的物理化学稳定性和合适的等排吸附热以及高的CO2/N2-理想选择性赋予了这些多级多孔碳材料在气体吸附和分离方面的巨大潜力。
The advent of microporous organic polymers (MOPs) has delivered great potential in gas storage and separation (CCS). However, the presence of only micropores in these polymers often imposes diffusion limitations, which has resulted in the low utilization of MOPs in CCS. Herein, facile chemical activation of the single microporous organic polymers (MOPs) resulted in a series of hierarchically porous carbons with hierarchically meso-microporous structures and high CO, uptake capacities at low pressures. The MOPs precursors (termed as MOP-7-10) with a simple narrow micropore structure obtained in this work possess moderate apparent BET surface areas ranging from 479 to 819 m(2) g(-1). By comparing different activating agents for the carbonization of these MOPs matrials, we found the optimized carbon matrials MOPs-C activated by KOH show unique hierarchically porous structures with a significant expansion of dominant pore size from micropores to mesopores, whereas their microporosity is also significantly improved, which was evidenced by a significant increase in the micropore volume (from 0.27 to 0.68 cm(3) g(-1)). This maybe related to the collapse and the structural rearrangement of the polymer farmeworks resulted from the activation of the activating agent KOH at high temperature. The as-made hierarchically porous carbons MOPs-C show an obvious increase in the BET surface area (from 819 to 1824 m2 g-1). And the unique hierarchically porous structures of MOPs-C significantly contributed to the enhancement of the CO, capture capacities, which are up to 214 mg g(-1) (at 273 K and 1 bar) and S2 mg g(-1) (at 273 K and 0.15 bar), superior to those of the most known MOPs and porous carbons. The high physicochemical stabilities and appropriate isosteric adsorption heats as well as high CO2/N-2 ideal selectivities endow these hierarchically porous carbon materials great potential in gas sorption and separation.